


Blood Bonds

by Daxolotl



Category: Supergirl (TV 2015)
Genre: (kind of), Alternate Universe - Vampire, Blood, Blood Bond, F/F, Near Death Experiences, Non-Graphic Violence, Red Kryptonite
Language: English
Status: In-Progress
Published: 2018-11-05
Updated: 2018-11-05
Packaged: 2019-08-19 10:41:22
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,640
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16533008
Author URL: https://archiveofourown.org/users/Daxolotl/pseuds/Daxolotl
Summary: "What can you tell me about Kryptonian Blood Bonding?" Alex asks."I am sorry, but that information is restricted to members of the House of El.""Alura, do a full scan of Alex," Kara says, sighing.There's a few long seconds of silence, before the hologram flickers. "Apologies. Welcome, Alexandra of the House of El."Alex blinks."Congratulations on your joining to our house. How may I assist you?"





	Blood Bonds

"Kara. Just…listen to yourself," Alex says, taking a cautious step forward.

"Oh, cut the big sister act, Alex! We have _never_ been sisters. We don't share blood." Kara snaps, spinning around to face her. Her eyes are wild, red lines glowing over her skin. "And you know what the sad truth is? Without me? You have no life. And that kills you!"

Alex gasps, tears in her eyes, as Kara approaches.

"Deep down? You hate me. And that's why you killed my aunt."

"Kara, no," Alex says, taking a step forwards again and reaching out to try and take her hand. "I don't hate you, I could never—"

Kara's hand snaps outwards, grabbing Alex's wrist. "Don't. Touch. Me. And don't you _dare_ lie to me."

There's a sickly snapping noise, and Alex's whole world becomes pain. The last thing she sees is Kara's face turn into an angry grimace, before something hits her chest and everything goes black.

_ _ _

Pain. Pain. More pain. And the smell of burnt toast, for some reason? That feels wrong.

"Agent Danvers, Lord has finished a device to cure Supergirl, are we ready to move…oh, god, Alex!"

Alex knows that voice. Hank? No. Not Hank. That name isn't right. J'onn?

Yeah, that sounds better.

"Alex, hold on. Stay with me, you'll be okay. Damn it, what did she _do_ to you?"

Everything's blurring, his words sounding far away behind the ringing in her ears. Was the ringing always so loud?

"Hold on! Alex!"

_ _ _

Beeping. Incessant, annoying beeping.

At least the pain's gone now. That's good. Probably.

"We captured Supergirl. Your device worked. She's unconscious for right now, on the sunbed." J'onn, again. "How's Alex doing?"

"She's stable. Or. Well. As stable as she can be, considering."

She doesn't like that voice. It makes her want to punch someone.

"If she dies, Lord, I want you to know that I'm holding you personally responsible."

"Don't worry. She dies? I'll hand myself into your custody. I never meant to hurt her."

"No. Just everyone else."

_ _ _

"Any change?" Another voice. Deeper. Not as deep as J'onn's, though. Gentle. A friend of Kara's.

"She comes and goes. Right now's a good time. She might even be able to hear us. But sometimes…"

"But-but she'll be okay, right? She'll recover?" That voice, she definitely feels like she knows. The civilian Kara hangs around with all the time. The one who was in love with Kara. She supposes everyone's a little bit in love with Kara.

"There's no way to be sure."

_ _ _

"Alex? _Alex_! No!"

Kara. There she is.

"Oh, Rao, Alex, no no no no no! I'm sorry, Alex, I'm so so sorry!"

Her voice is frantic, desperate.

"Wake up for me, Alex, please. Please, I need you, I'm so sorry, I never wanted to hurt you. I never wanted this, Rao. Please. _Please_!"

There's sobbing, for a long time. 

Every part of Alex wants to reach out, to comfort the crying girl she knows is near to her. But no part of her body responds.

"I didn't…I didn't mean it. I didn't mean to. I'm so so sorry. Please don't leave me alone."

_ _ _

"She's going to be okay, right?"

The words are met with silence, the beeping of Alex's life support machinery her only answer.

"…Right?"

"Kara. I know this is difficult, but I can't…hear her, any more. Her thoughts are just white noise when I try to read them. There's a possibility she could make some level of recovery, but…at this point, it's likely that most of the damage is…irreversible."

"But she can make a recovery." Kara Danvers, always the optimist. Alex wants to laugh.

"There's a slim chance that she'll wake up. But beyond that…anything else is almost impossible."

"No. That's not…that's…" Kara's words jumble together, a panicked rush. "We have to _do_ something. She's my family. She's my _blood_! _Save her_!"

If Alex had control over any part of her body, she'd cry. Her blood. If only.

"No. Don't touch me. You're all giving up on her? Come on, there must be something! Some piece of technology, Coluan or Martian or Kryptonian, that can s…"

There's silence for a few seconds.

"I'm going to save her," Kara says. And with the determination in her voice, Alex believes her. She believes her sister can do anything she puts her mind to.

_ _ _

Then the pain comes back.

_ _ _

Beeping. Again. Why is it always beeping.

Alex's eyes open slowly, and she squints against bright yellow lights above her. She groans, raising a hand to cover her eyes and rub them.

"Alex!" a voice says from one side of the room, far too loudly, and a second later Kara is by her side.

Alex groans again. "Too loud, too bright. Too early. Five more minutes."

There's a rush of wind in the room, and when Alex next opens her eyes the lights of the room have been dimmed. There's a faint yellow glow coming from around her, and she makes a move to sit up, looking at Kara. She's a sight for sore eyes. Literally sore eyes, those lights were really bright.

"Everything aches. What happened? And why am I on your sunbed?" She taps her fingers against the warm, glowing glass she was lying on.

Kara freezes. "You, um. You don't remember?"

"I remember…you, under Lord's Red Kryptonite. We were talking, and then…I don't know what happened."

Kara's arms cross protectively over her chest. "I, um. I broke your wrist, then punched you across the room. You went through two walls."

Alex blinks a few times, blankly. "You punched me through two walls? I feel…remarkably fine, considering. Are you getting weaker, Kar?"

The attempt at humour falls flat. "It was….it was really bad, Alex. You weren't…you could ask the doctors, if you wanted to know all of it. But…it was really bad."

Alex reaches out, only for Kara to flinch and step away. "Hey, hey. Kar. It's okay. I'm okay. No permanent damage, right?"

"You could've died, Alex. You…the doctors say you probably would have, if I hadn't…" Kara trails off.

"..If you hadn't what?"

"It's, um. I should let you get more used to being awake; you've been through a lot. The doctors need to take a look at you, J'onn will want to give you a hug, it's really…"

Alex knows when Kara is trying to avoid a topic.

"Kara. What did you do?"

_ _ _

"Alura."

The hologram appears in front of Alex – the face so similar to Astra's that Alex can't help but find it a little unnerving. She's in a wheelchair, but she feels like she doesn't need it. She feels fine. More than fine. Way better than someone who was apparently thrown through a wall less than a week ago should feel. "Greetings, Alexandra of the House of Danvers."

"What can you tell me about Kryptonian Blood Bonding?" she asks, rocking her wheels back and forth.

"I am sorry, but that information is restricted to members of the House of El."

Alex grits her teeth, ready to curse or threaten or try to order an override, when Kara's voice comes from behind her, in the doorway.

"Alura, tell us about Kryptonian Blood Bonding."

"Of course, Kara," the hologram doesn't smile, doesn't react genuinely, but Alex supposes the lack of house title is the closest it can get. "Kryptonian Blood Bonding is an outdated practise formerly performed during the joining of Houses. It brought longevity and good health, binding Houses together and providing greater vitality to each partner. It was also used to aid those who were seriously ill, providing them with the vigour of a healthy individual from another House. Eventually, Krypton's understanding of genetic engineering advanced such that it became unnecessary for any health reasons, though some traditionalists still practised it during the joining of Houses all the way up to the fall of Krypton."

Alex frowns, deeply. She's missing something. Something Alura isn't saying. "How does the ceremony take place? What does it involve?"

"I am sorry, but that information is restricted to members of the House of El."

"Alura, do a full scan of Alex," Kara says, sighing.

There's a few long seconds of silence, before the hologram flickers. "Apologies. Welcome, Alexandra of the House of El."

Alex blinks.

"Congratulations on your joining to our house. How may I assist you?"

She looks from the hologram, to the anxious-looking Kara, and back again. "I think that answers my question, thanks."

She wheels herself away, out of the room. Kara doesn't try to stop her.

_ _ _

She doesn't know how to deal with it all. Her sister told her they weren't sisters, tried to kill her, saved her, and then, in saving her…changed her.

And when she doesn't know how to deal with something, she retreats inwards. She always has.

Alex rotates her shoulder before going back to hitting the punching bag. She's made a fast recovery. Too fast. The sunbed and the lamps have healed her from injuries which, she now knows, should've killed her. She read her chart. After she finished reading, her one take-away from it was that it would've been faster to list the bones that _weren't_ broken. 

She'd been a wreck, barely clinging on to life. The fact that she didn't die in Kara's apartment was a miracle. The fact that she didn't die at all is Kryptonian science. And now, five days after having her life saved, she's better than she's ever been.

She punches the bag again, once, twice, before the chain holding it up snaps and it flies across the room.

That's the other thing. It's been happening more and more since she's been on the sunbeds. She's been getting stronger. Faster. Yesterday, she picked up on a conversation happening in the control room when she was all the way in the medbay. She doesn't know how much further it'll go, but it scares her.

She's not human any more. She's something else. And she doesn't know how to deal with that.

So, here she is.

The door to the training room opens behind her.

"Try not to overdo it. You were in hospital a few days ago," J'onn advises, stepping into the room. "Still avoiding Kara, I see?"

Alex shrugs, hanging up another punching bag. "We'll talk when we've processed everything. It's a lot, Hank."

Her mentor grabs the bag, holding it steady as she starts to pummel it into submission. "Oh?"

Alex quirks an eyebrow between punches. "First, some version of her, some _imposter_ , punched me into a coma. Then, the real her found the one way she could save my life. That alone is enough to have to deal with. Do I thank her, or punch her?" Her punches get harder, J'onn struggling to hold the bag steady. "And then, I find out that the way she saved me was to give me _her blood_. To turn me into…some hybrid. What even _am_ I any more, J'onn? I'm meant to be a human, fighting to protect humans. And now, I'm something else. Something nobody knows how to deal with!" One last blow, hard, and J'onn staggers backwards, rubbing his shoulder. "…Least of all the sister who took my humanity when all I ever wanted was to give her some of her own."

He stares at her. Truly stares. And she feels her walls begin to crumble.

"I don't know what I am anymore," she says, breaking down. He steps forwards, wrapping her in a hug and holding her close as she sobs against her chest.

Eventually, her sobbing begins to subside.

"You're Alex Danvers," J'onn murmurs, soft against her ear. "You're one of the two most important people in this world to me. Is that enough?"

"…It's a start," Alex says, wetly. "I can work with that."

She takes a step back, nodding to J'onn before a frown overtakes her features. The room is blurring. Everything is spinning, suddenly. She feels faint. "J'onn. I think I might've….overdone it a little," she says, as the ground rushes up to meet her.

_ _ _

Beeping. Can someone please shut up that damnable beeping? Everything's too loud, and too cold.

She opens her eyes blearily, sitting up on the sunbed and wrapping her arms around herself. "What happened this time?"

Kara's keeping her distance, still, while Doctor Hamilton and J'onn stand nearby. They share a glance between themselves, and she doesn't like that. Finally, Amelia speaks.

"Your body seems to have stopped absorbing solar radiation. Yellow sunlight isn't affecting it any more. We don't know if that's just your body resetting to normal, or if the blood bonding didn't work properly." The former option, she likes. The latter, not so much. "Either way, your body isn't fully healed. You passed out."

"Why's it so cold in here?" Alex asks, teeth chattering. There's another worried look.

"Alex, with the sunlamps on, the room is sitting at 77 degrees Fahrenheit," J'onn says, cautiously. "What other symptoms do you have?"

Alex tries to think as Kara superspeeds away, bringing a blanket and passing it to the doctor for her to hand over. It doesn't help much, but she curls up within it anyway. "Uh. I'm lethargic. Cold. Thoughts are fuzzy. Noises are too loud, got a splitting headache like the worst hangover. I'm really cold."

They share another worried look.

"Can you all _stop_ looking at each other like that? It's infuri…inf…it makes me angry."

Doctor Hamilton walks over to a drawer, withdrawing a needle and syringe. "I'd like to take some blood from you to run some tests. Is that alright?"

Alex glances between Doctor Hamilton and Kara. "It's her blood, not mine. Maybe you should ask her."

Kara flinches, looking down and biting her lip. Alex feels bad immediately. Kara was trying to help. There was no other option. But the _otherness_ of herself just feels…so unnerving.

There's a stabbing pain in her arm, and Doctor Hamilton takes a handful of vials of blood. Alex finds herself growing lightheaded with every second that passes, staring at the blood as it fills the fragile glass vials. "Such a pretty colour," she murmurs, and passes out again.

_ _ _

The next time she wakes up, she pretends she hasn't. She lies back, listening to the conversation around her. She feels like death, freezing cold even with the sunbed and the heated blanket she's beneath.

"From what I can see, her blood is totally normal in all regards. Nothing out of the ordinary in any tests, despite her worsening symptoms."

Blood…Alex's mind starts working, slowly. It's sluggish, but something feels just out of reach.

"…Exactly how normal is it?" Kara asks, at the same moment Alex manages to reach that point.

"…One hundred percent human," Amelia says, realisation clear in her voice.

J'onn's low rumbling voice is the next to speak up. "Human, when it should be at least partially Kryptonian."

She's close to a solution. She can feel it in her bones. Her blood's human when it shouldn't be.

"Her body seems to have rejected the blood bonding procedure. She's replaced the Kryptonian blood with human blood, but that...doesn't explain why her condition is worsening."

It explains every part of it. She knows why she's getting sick. Why she's worsening. She's slow, damn her mind feels so slow right now, but she's still reached the answer.

"…Her body had already started changing. And human blood can't support a Kryptonian body, even one that's still mostly human. I did this to her. I just wanted to help, and instead I _broke_ her." Kara's voice has an edge of panic to it. "I just wanted to fix one mistake, and instead I've done this to her. What sort of person am I?"

Alex opens her eyes slowly. "A hero," she murmurs, and the occupants of the room collectively stare at her. "My sister. And also? The girl who's gonna save my life. Again."

She clears her throat, and Doctor Hamilton passes her a glass of water. She takes a few sips, whetting her throat before handing it back.

"You said my blood had reverted back to human blood, right?" It's a rhetorical question, and she ignores the nod she gets in response. "And when I spoke to Alura, she said blood bonding was used to give a sick Kryptonian the health of whoever's blood they took, right?" Another nod, this one only from Kara. Alex takes a deep breath. "With Kryptonians, your bodies were engineered to be able to do that. They learn from the blood they take in, adapting to it rapidly. But with me? My body is still human…mostly. My body doesn't know _how_ to produce Kryptonian blood."

"So what are you suggesting?" J'onn asks, gently.

"A transfusion." Alex bites her lip. "It's a lot to ask, Kara, but…I think your blood can help me. I don't know how much I'd need, but, if my body can't produce its own Kryptonian blood…"

"I'll do it," Kara says, already rolling up one of her sleeves. "We'll need a Kryptonite needle, Doctor. We don't know how much time Alex has, so if we're going to do this…we should do it now" she says, and Doctor Hamilton rushes into action. 

Kara sits down at Alex's bedside, the closest she's been since the incident, and takes a breath.

"Kara? This is going to work." Alex says, softly.

"I hope so."

A device is wheeled into place between the two of them, and Alex recognises it from her medical school days. A direct blood transfusion pump. "We'll start with one unit. That shouldn't weaken Supergirl, but should be enough to tell us if it's having an effect on Alex." 

She barely feels the needle enter her own skin, her arm feels so cold. There's a hiss of pain from Kara a few seconds later, and Alex glances over to see the glowing green needle pierce the superhero's skin. Kara closes her eyes, taking a few slow breaths.

"Are you okay?" Alex asks.

Kara opens her eyes and smiles gently, pain in the edges of her eyes. "I will be. And so will you."

The pump is switched on, and Alex lets out a gasp as she feels the flow of blood start.

"Oh, Rao," she murmurs, falling flat against the sunbed. Her eyes roll back. It feels like pure power pouring into her veins. She supposes, in a manner of speaking, that it is. "Oh, _Rao_."

Then laughter, giddy and light, fills the room. It takes her a few seconds to realise it's coming from her.

"Kara," her voice is slurring, sounding almost drunk. "Is this how you feel all the time? I never want it to stop. Oh my god, I never want it to stop."

She doesn't feel cold any more. She feels warm – warm like the sun, like the lamps surrounding her, like Kara. And, as the blood flows from Kara into her, she asks herself how she could ever have felt like this was a curse. How could she have blamed Kara for giving her this gift? For saving her?

She forces her eyes open to look at Kara. For a moment, her vision blurs, glimpsing through reality itself, and then she sees her. Sees all of her. She smiles brightly. "Oh, my gorgeous alien girl."

"Blood of mine," Kara responds. "Zrhueiao."

They stare at one another for the next minutes, as Alex feels power pour through her.

The pump turns off, and Alex starts giggling again. "D'y'think it worked?" she asks, remembering the other occupants of the room and looking at them with a grin.

J'onn rolls his eyes and steps over to pat her on the shoulder, smiling softly. "You had us worried there, Alex."

Doctor Hamilton steps forwards, removing the needle from Alex's arm and pressing a hand to her forehead to check the temperature. "I want to run more tests once the blood has had a chance to fully circulate your system. For now…rest, and stay under the sun lamps. Supergirl, you'll need sun too to help recover from that blood donation."

Kara glances at the sunbed as she pulls the Kryptonite needle from her arm. "Yeah. Okay. I'll, uh, go for a fly."

"There's room for two on this sunbed, Kar," Alex grumbles, all formality forgotten. "And even if there wasn't, we've shared smaller beds than this. This is luxurious compared to my single back in Midvale."

Kara looks torn, biting her lip with worry. "I…are you sure? I don't want to hurt you again, and…"

Alex rolls on to one side and lifts the blanket. "Get in here, grumpy face. You're not gonna hurt me. You never have." Kara opens her mouth to disagree, but Alex cuts her off. "You haven't. You weren't acting like yourself under Red Kryptonite. You'd _never_ hurt me. I trust you with my life, okay, so just…get in here and recover some of your fancy Kryptonian blood? Please?"

Kara smiles faintly, stepping close and slipping on to the sunbed next to Alex. The first time Kara brushes against Alex, she freezes, but Alex just smiles at her reassuringly until she starts moving again. It's a tight fit, but they both manage to get under the blankets without either of them falling off, and Alex immediately curls around her sister to hold her close, breathing her in.

Alex strokes her fingers through Kara's hair, and Kara shivers under her touch. "Good. Now, rest and enjoy the sunshine, sunshine girl. I know I am."

**Author's Note:**

> _I initially planned to upload this entire story for Halloween, but with the time I've had for the past month, it's been sitting as a WIP. And today, after finally finishing the most recent scene, I decided I wanted to upload it as a multi-chapter experience. There should be one or, more likely, two more chapters._


End file.
